There are several challenges associated with the deployment of fiber-optic cable in water. To prevent wasteful, unrestrained payout of the cable, especially in deep water, tension is typically applied to the cable by way of capstans or hand tension. These previous techniques have draw-backs, however, such as cable damage in the event of a cable snag, limited sequential in-line sensor deployment capability, and lack of precision/control. A need exists for a system with improved functional capability and greater control of optical-cable deployment.